In existing aircraft, the engines such as double-flow and double-body jet engines, are suspended under the wings or added to the fuselage by complex attachment devices, also called EMS (engine mounting structure), or even attachment strut. The attachment struts usually employed have a rigid structure, called primary structure. This primary structure generally forms a box, that is to say that it consists of the assembly of bottom and top spars connected together by a plurality of transverse stiffening ribs, situated inside the box. The spars are arranged on the bottom and top faces, while lateral panels close the box on the lateral faces.
As is known, the primary structure of these attachment devices is designed to allow the transmission to the wings of the static and dynamic forces generated by the engines, such as the weight, the thrust, or even the different dynamic forces.
In the solutions known from the prior art, the transmission of the forces between the engine and the primary structure is conventionally ensured by attachment means consisting of a front engine tie, a rear engine tie and a device for absorbing the thrust forces. These elements together form an isostatic tie system.
Usually, the front engine tie is fixed to the outer shell of an intermediate case or onto the fan case, as is disclosed in the document FR 3 014 841. Alternatively, this front engine tie can be added to the hub of the intermediate case, linked by radial arms to the above mentioned outer shell. For its part, the rear engine tie connects the primary structure to the engine exhaust case, situated at the rear end of this engine.
With this type of configuration, forces of high intensity have to be absorbed by the rear engine tie, in particular the forces linked to the torsional moment. To ensure the absorption of these significant forces, the rear engine tie usually has a significant bulk, particularly in the transverse direction. This strong bulk can, for example, be reflected by the presence of local protuberances at the two lateral ends of the rear engine tie. This causes, in the secondary jet, aerodynamic disturbances which are detrimental to the overall performance of the engine. Furthermore, it results in an over dimensioning of the surrounding aerodynamic fairings, such as the rear aerodynamic fairing (or Aft Pylon Fairing, APF), the width of which has to be adapted accordingly. These over dimensionings of the surrounding fairings also cause drag.